There has been dramatic resurgence of interest in surgical treatment of emphysema, particularly "lung volume reduction" procedures. Recent studies have demonstrated improvements in pulmonary function, lung mechanics, exercise tolerance, and quality of life in selected patients following volume reduction procedures. However, considerable uncertainty remains regarding overall benefit, optimal patient selection, operative techniques, and duration of response. This summarizes current approaches to lung volume reduction surgery, available clinical outcome information, selection criteria, and physiologic mechanisms of response, and discusses the potential role for surgical volume reduction in treatment of emphysema. Recent data appear to support the efficacy of bilateral staple lung volume reduction surgery in patients with severe symptomatic heterogeneously distributed emphysema. Further studies will be needed to determine relative value of different operative techniques and benefit in patients with other clinical presentations.

To define the incidence of bleeding complications from central venous access procedures performed by a critical care service in patients with disorders of hemostasis.

Clinical diagnosis of nosocomial pneumonia in ventilated patients remains a challenge in the ICU as none of the clinical biological and radiologic parameters can predict its diagnosis. To our knowledge, however, the accuracy of direct visualization of the bronchial tree has never been investigated.

To determine the contributions of (1) chest wall (Pcw) and (2) lung elastic recoil pressure (PL) to (3) total elastic recoil pressure exerted by the respiratory system (Prs) in 18 patients (12 men) aged 66 +/- 6 years (mean +/- 1 SD) with severe emphysema who underwent video-assisted thoracoscopic bilateral lung volume reduction surgery under paralyzed (vecuronium) general anesthesia (isoflurane).

Adult croup is a distinct disease entity that probably represents a heterogeneous clinical syndrome. Three cases of adult laryngotracheitis characterized by upper airway infection and progression to airway obstruction are illustrated. Close observation and prompt decisions regarding airway intervention are critical in effective management, and complete resolution is expected.

In search of a better universal marker of tissue inflammation in allergic reactions, we studied platelet activation and its relation to allergic asthma in sheep.

In this prospective study, we measured the ST segments, heart rate-systolic BP product (RPP), respiratory rate to tidal volume ratio (RVR), and pulse oximetry saturations of patients in our medical/cardiac ICUs before and during weaning from mechanical ventilation. Ninety-three patients were enrolled with a mean age of 66.5 +/- 15.0 years (mean +/- SD), mean acute physiology and chronic health evaluation (APACHE) II score of 16.0 +/- 6.9, and mean duration of mechanical ventilation of 5.2 +/- 8.6 days. Forty-nine patients had coronary artery disease (CAD). Six of 93 patients (6.4%) experienced ECG evidence of ischemia during weaning. Five of these six had a precedent history of CAD and four failed initial weaning attempts (22% of patients with CAD who failed weaning). The RPP, for the group as a whole, increased significantly during weaning from 12.0 +/- 3.1 to 13.4 +/- 4.0 mm Hg.bpm.10(3) (p<0.01). The rate to volume ratio did not change significantly during weaning, except in the subgroup of patients who failed to wean, in whom it increased from 98.4 +/- 45.2 to 124.9 +/- 54.9 bpm/L (p<0.05). Oxygenation also decreased significantly from 0.98 +/- 0.02 to 0.96 +/- 0.03 and was significantly associated with weaning failure (risk ratio [RR]=3.9; 95% confidence interval [CI]=1.7 to 9.0). Thirty-seven patients failed the initial weaning attempt. Cardiac ischemia (RR= 1.8; 95% CI=1.0 to 3.4) and an increased RVR (RR=1.7; 95% CI=0.9 to 3.4) tended to increase the risk of weaning failure. Cardiac ischemia, although infrequent (6%) in the general population of weaning medical/cardiac ICU patients, should be considered in patients with CAD who fail to wean.

Pressure support ventilation (PSV) provides a range of ventilatory support from partial respiratory muscle unloading, where inspiratory work is shared between the patient and the mechanical ventilator, to total respiratory muscle unloading, where inspiratory work is performed solely by the ventilator. This study is designed to determine if minimizing work fully accounts for relief of tachypnea during PSV. We examined respiratory parameters over a range of PSV that includes the crossover from partial to total respiratory muscle unloading. Eight studies were obtained on seven intubated patients in respiratory failure. Ventilation, occlusion pressure (P0.1), and patient inspiratory work (WOBinsp) were measured while PSV was varied. In all patients, WOBinsp decreased as PSV increased. The level of PSV where WOBinsp was minimized was identified; this marked the crossover from partial to total respiratory muscle unloading. Frequency decreased with increasing PSV but remained elevated (range, 22 to 38 breaths/min) at the crossover. Frequency was normalized only at PSV levels 131 to 193% of the levels of pressure at the crossover. Tidal volume (VT) changed little during partial support and averaged 5.9 mL/kg at the crossover. VT increased only on PSV providing total unloading. Six of seven patients exhibited increasing static compliance with increasing VT suggesting alveolar recruitment. P0.1 tracked WOBinsp over the entire range of PSV (r = 0.95, p < 0.001). The normalization of frequency observed above the crossover coincided with increasing VT rather than decreasing work. These observations suggest that reflexes resulting from increased VT and/or alveolar recruitment may have contributed to the normalization of frequency.

We tested the hypothesis that patients with COPD can use dyspnea ratings obtained from a prior graded exercise test as a target to reliably produce specific exercise intensities.

To assess objectively measured, long-term trends in compliance with physician-prescribed metered-dose inhaler (MDI) use during a clinical trial.

Upper airway resistance syndrome (UARS) is a sleep-disordered breathing syndrome characterized by complaints of daytime fatigue and/or sleepiness, increased upper airway resistance during sleep, frequent transient arousals, and no significant hypoxemia. Of a population of 110 subjects (58 men) diagnosed as having UARS, we investigated acute systolic and diastolic BP changes seen during sleep in two different samples. First, six patients from the original subject pool were found to have untreated chronic borderline high BP, and were subjected to 48 h of continuous ambulatory BP monitoring before treatment and another 48 h of BP monitoring 1 month after the start of nasal-continuous positive airway pressure (N-CPAP) treatment. Five of six subjects used their equipment on a regular basis and had their chronic borderline high BP completely controlled. No change in BP values was seen in the last subject, who discontinued N-CPAP after 3 days. A second protocol investigated seven normotensive subjects drawn from the initial subject pool. Continuous radial artery BP recording was performed during nocturnal sleep with simultaneous polygraphic recording of sleep/wake variables and respiration. BP changes were studied during periods of increased respiratory efforts and at the time of alpha EEG arousals. Increases in systolic and diastolic BP were noted during the breaths with the greatest inspiratory efforts without significant hypoxemia. A further increase in BP was noted in association with arousals. Three of these subjects also underwent echocardiography during sleep, which demonstrated a leftward shift of the interventricular septum with pulsus paradoxus in association with peak end-inspiratory esophageal pressure more negative than -35 cm H2O. Our study indicates that, in the absence of classic apneas, hypopneas, and repetitive significant drops in oxygen saturation (below 90%), repetitive increases in BP can occur as a result of increased airway resistance during sleep. It also shows that, in some patients with both UARS and borderline high BP, high BP can be controlled with treatment of UARS. We conclude that abnormal upper airway resistance during sleep, often associated with snoring, can play a role in the development of hypertension.

We present the first case of mediastinitis and the third case of pneumonia attributed to Actinomyces odontolyticus. The first patient presented 10 months after single-lung transplant with a subacute apical infiltrate in the native lung and responded to therapy with oral penicillin. The second patient developed pyogenic mediastinitis 25 days after a heart-lung transplant and required sternal debridement and intravenous penicillin. We also review the literature on thoracopulmonary infections due to A odontolyticus.

Systemic embolization is a common complication of left atrial myxoma; however, coronary embolism leading to acute myocardial infarction is rare. The use of echocardiography has increased the detection of intracardiac tumors when signs and symptoms are not evident. Echocardiography is the diagnostic procedure of choice in the initial evaluation of patients with suspected left atrial myxoma.